birthwt {MASS}R Documentation

Risk Factors Associated with Low Infant Birth Weight

Description

The birthwt data frame has 189 rows and 10 columns. The data were collected at Baystate Medical Center, Springfield, Mass during 1986.

Usage

birthwt

Format

This data frame contains the following columns:

low
indicator of birth weight less than 2.5kg
age
mother's age in years
lwt
mother's weight in pounds at last menstrual period
race
mother's race (1 = white, 2 = black, 3 = other)
smoke
smoking status during pregnancy
ptl
number of previous premature labours
ht
history of hypertension
ui
presence of uterine irritability
ftv
number of physician visits during the first trimester
bwt
birth weight in grams

Source

Hosmer, D.W. and Lemeshow, S. (1989) Applied Logistic Regression. New York: Wiley

References

Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.

Examples

attach(birthwt)
race <- factor(race, labels = c("white", "black", "other"))
ptd <- factor(ptl > 0)
ftv <- factor(ftv)
levels(ftv)[-(1:2)] <- "2+"
bwt <- data.frame(low = factor(low), age, lwt, race,
    smoke = (smoke > 0), ptd, ht = (ht > 0), ui = (ui > 0), ftv)
detach("birthwt")
options(contrasts = c("contr.treatment", "contr.poly"))
glm(low ~ ., binomial, bwt)

[Package MASS version 7.2-33 Index]